Format

Send to

Choose Destination
Mol Cell. 2007 Jan 26;25(2):181-92.

Calcium blocks formation of apoptosome by preventing nucleotide exchange in Apaf-1.

Author information

1
Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA.

Abstract

Apaf-1 plays an essential role in apoptosis. In the presence of cytochrome c and dATP, Apaf-1 assembles into an oligomeric apoptosome, which is responsible for the activation of procaspase-9 and the maintenance of the enzymatic activity of the processed caspase-9. Regulation of apoptosome assembly by other cellular factors is poorly understood. Here we report that physiological concentrations of calcium ion negatively affect the assembly of apoptosome by inhibiting nucleotide exchange in the monomeric, autoinhibited Apaf-1 protein. Consequently, calcium blocks the ability of Apaf-1 to activate caspase-9. These observations suggest an important role of calcium homeostasis on the Apaf-1-dependent apoptotic pathway.

PMID:
17244527
DOI:
10.1016/j.molcel.2006.12.013
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center